public class GuestbookServlet extends HttpServlet {
    public void doGet(HttpServletRequest req,HttpServletResponse resp)
        throws IOException {
                            UserService userService =UserServiceFactory.getUserService();
                            User user = userService.getCurrentUser();
                            if (user != null) {
                                resp.setContentType("text/plain");
                                resp.getWriter().println("Hello, " +
                                user.getNickname());} 
                                else
{ resp.sendRedirect(userService.createLoginURL(req.getRequestURI()));
} } }
